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Biomedical subjects

M Weiss

Publications and source records attributed to M Weiss.

At least 19 recordsLinked to original sources
PubMed1992

Adjunctive thrombolytic therapy for angioplasty in ischemic rest angina: results of a double-blind randomized pilot study.

OBJECTIVES: A multicenter pilot study was instituted to assess the role of intracoronary thrombolytic therapy during angioplasty for ischemic rest angina. BACKGROUND: Acute thrombotic coronary occlusion is increased during angioplasty for unstable angina, and intracoronary thrombolytic agents have been used to maintain patency. Prophylactic use of intracoronary thrombolytic agents has been advocated in certain high risk subgroups, although no studies have randomized therapy. METHODS: Ninety-three patients with either unstable angina and pain at rest (trial A, 66 patients) or postinfarction pain at rest (trial B, 27 patients) were randomized in double-blind fashion to administration of either intracoronary urokinase, 150,000 U, or saline solution placebo given immediately before angioplasty. Cineangiograms of the culprit lesion were recorded and analyzed in blinded fashion by a core laboratory for definite or possible (haziness) filling defects 15 min after angioplasty or after acute closure. RESULTS: Urokinase decreased filling defects at 15 min after angioplasty in comparison with placebo (14% vs. 29%, respectively, p = 0.08). Four patients in each treatment group developed acute vessel closure. However, although urokinase significantly reduced the incidence of filling defects in trial A (3% vs. 23%, p = 0.03), the drug had no effect at the selected dose in trial B (42% vs. 43%, respectively). Acute vessel closure occurred significantly more frequently in trial B than in trial A, and urokinase at the selected dose also had no effect. Ischemic events after angioplasty appeared to be related more to dissection than to thrombosis, although redilation, which was more frequent after placebo administration, may have reduced their incidence as well as that of acute closure. CONCLUSIONS: These data suggest a possible role for intracoronary urokinase during angioplasty for unstable angina. The lack of effect after infarction may represent a greater thrombus burden or degree of plaque disruption. A trial utilizing higher doses of urokinase in a larger patient group is in progress.

Angina, Unstable↗
PubMed1992

The "retinoic acid syndrome" in acute promyelocytic leukemia.

OBJECTIVE: To describe a novel complication of therapy with all-trans retinoic acid in patients with acute promyelocytic leukemia. DESIGN: Case series. SETTING: Comprehensive cancer center. PATIENTS: Consecutive patients with a morphologic diagnosis of acute promyelocytic leukemia who underwent remission induction treatment with all-trans retinoic acid, 45 mg/m2 body surface area per day. MEASUREMENTS AND RESULTS: Nine of 35 patients (26%; 95% CI, 9% to 52%) with acute promyelocytic leukemia who were treated with all-trans retinoic acid developed a syndrome consisting primarily of fever and respiratory distress. Additional prominent signs and symptoms included weight gain, lower-extremity edema, pleural or pericardial effusions, and episodic hypotension. The onset of this symptom complex occurred from 2 to 21 days after starting treatment. Three deaths occurred; post-mortem examinations in two patients showed pulmonary interstitial infiltration with maturing myeloid cells. Six other patients survived, each achieving complete remission (five patients with all-trans retinoic acid only; 1 patient with chemotherapy). In six of the nine cases, the onset of the syndrome was preceded by an increase in peripheral blood leukocytes to a level of at least 20 x 10(9) cells/L. Certain therapeutic interventions, including leukapheresis, temporary cessation of therapy with all-trans retinoic acid, and cytotoxic chemotherapy in moderate doses were not useful after respiratory distress was established. However, the administration of high-dose corticosteroid therapy (dexamethasone, 10 mg IV intravenously every 12 hours for 3 or more days) early in the course of the syndrome resulted in prompt symptomatic improvement and full recovery in three of four patients. CONCLUSIONS: The use of all-trans retinoic acid to induce hematologic remission in patients with acute promyelocytic leukemia is associated in some patients with the development of a potentially lethal syndrome that is not uniformly accompanied by peripheral blood leukocytosis. Early recognition of the symptom complex of fever and dyspnea, combined with prompt corticosteroid treatment, may decrease morbidity and mortality associated with this syndrome.

Adult↗
PubMed1992

Assessment of global and regional left ventricular performance at rest and during exercise after thrombolytic therapy for acute myocardial infarction: results of the Thrombolysis in Myocardial Infarction (TIMI) II Study.

Global and regional left ventricular performances were evaluated with equilibrium radionuclide angiocardiography in patients in the Thrombolysis in Myocardial Infarction (TIMI) II trial at the time of hospital discharge. Studies at rest were available in 1,162 (69%) of the invasive and 1,150 (69%) of the conservative strategy patients, and exercise studies in 1,133 (67%) of the invasive and 1,145 (69%) of the conservative patients. Repeat studies were performed at the time of 6-week follow-up. Global and regional ejection fraction at rest were both comparable in patients assigned to each of the treatment strategies. However, at the time of hospital discharge patients in the invasive strategy had normal exercise responses more frequently (29.7 vs 25.8% p = 0.01), greater peak exercise LV ejection fraction (54.8 +/- 13.8% vs 53.1 +/- 14.1%, p = 0.004), greater exercise--rest change in LV ejection fraction (3.7 +/- 6.7% vs 2.7 +/- 7.2%, p less than 0.001) and greater peak exercise infarct zone regional ejection fraction (53.2 +/- 31.1% vs 50.3 +/- 33.0%, p less than 0.001) than patients assigned to the conservative strategy. At 6-week follow-up these differences between treatment strategies were no longer evident. When data were restricted to those collected at comparable work loads, similar differences in hospital discharge exercise performance between invasive vs conservative strategy patients were observed. Thus, there is a small transient difference in exercise global and regional LV performance associated with an invasive as opposed to conservative strategy after thrombolytic therapy. These differences are noted at the time of hospital discharge but not at 6 weeks, and are unlikely to confer clinical benefit.

Chi-Square Distribution↗
PubMed1992

Tumoral calcinosis of the ischium.

The authors report on a case of tumoral calcinosis of the ischium in a 63-year-old female. By means of this particular case a general review of the literature on pathogenesis, histological characteristics, the possible way of treatment and the prognosis of tumoral calcinosis is presented.

Bone Diseases↗
PubMed1992

Dynamics of drug distribution. I. Role of the second and third curve moments.

Conventionally, the dynamics of distribution in the body is evaluated by the so-called distribution half-life (e.g., t1/2, alpha); but then the mean time of the distribution process is underestimated due to the influence of elimination. By contrast, information about the dynamics of distribution contained in drug disposition curves can be extracted by the second and third curve moments, parameters that are related to the variance (VDRT) and skewness (SDRT) of residence time distributions; whereas the equilibrium state characterized by the volume of distribution (Vss), is determined by the mean residence time (MDRT) or the first curve moment. The approach represents a general noncompartmental analysis that is independent of a detailed structural model or a particular disposition function. Two parameters are introduced to characterize the dynamics of drug distribution: (i) the degree of departure of the system from "well-mixed" behavior of instantaneous distribution equilibrium (related to VDRT) and (ii) the mean time until equilibration is achieved (mean equilibration time, MEQT), which additionally depends on SDRT. Both parameters are quantitative measures of the dynamics of distribution and display explicit physical significance in terms of distribution within the corresponding noneliminating system. It is further shown that the so-called "distribution phase" in biexponential disposition curves is related to a monoexponential mixing curve of its corresponding noneliminating system with an equilibration or mixing half-time, t1/2,M = t1/2,alpha (V beta/Vss*), where Vss* denotes the distribution volume of the noneliminating system. The results are applied to mixing and disposition curves measured for acetaminophen in liver-ligated and intact rats, respectively.

Acetaminophen↗
PubMed1992

Intellectual capacity of subjects exposed to methimazole or propylthiouracil in utero.

Antithyroid drugs, considered the treatment of choice for hyperthyroidism during pregnancy, may have an adverse effect on intellectual development of the offspring. We examined the intellectual capacity of 31 subjects aged 4-23 years, born to women with Graves disease who received antithyroid drugs throughout pregnancy. Methimazole 40-140 mg/week (n = 15) or propylthiouracil 250-1400 mg/week (n = 16) was given. I.Q. was assessed using the Wechsler test appropriate for age. Twenty-five unexposed siblings served as controls. The exposed and unexposed groups did not differ with respect to the total I.Q. Both groups scored equally in verbal and performance skills and in each of six main subcategories of the tests. There was no difference between exposure to methimazole and propylthiouracil or between the higher (greater than 40 mg/week and greater than 600 mg/week, respectively) and lower dosages. All children were euthyroid at birth and none had goitre. We conclude that exposure to methimazole or propylthiouracil during pregnancy in doses sufficient to control maternal hyperthyroidism does not pose any threat to intellectual capacity of the offspring.

Adolescent↗
PubMed1992

[Provocable tumor of the cheek as a manifestation of so-called "infiltrating lipoma" of the masseter muscle].

We report on a 29-year-old male patient, who presented at our outpatient clinic with a 6-year history of progressive swelling of the right cheek. Contraction of the masseter muscle increased the swelling. MR-Imaging revealed a tumor measuring 2 x 3 cm, which was located within the masseter muscle. The histological diagnosis was infiltrating lipoma, which to our knowledge has not been described in this area before. This particular type of lipoma is extremely rare in the head and neck. The diagnostic and therapeutic management of infiltrating lipoma is discussed, and guidelines for adequate follow-up suggested. In addition, the authors review other sites of this tumor and describe its histological characteristics and differential diagnosis.

Adult↗
PubMed1992

Analysis of the diminished skin perfusion in elderly people by laser Doppler flowmetry.

Clinical observations suggest an age-associated decline in skin perfusion but there are few quantitative in vivo data on skin perfusion at various ages. We studied skin perfusion of the dorsum of the foot by determining the capillary blood flow velocity (CBFV) expressed in millivolts (mV), using laser Doppler flowmetry, in ten young and 12 elderly men. Our data revealed that, at 32 degrees C skin temperature, the CBFV oscillations (vasomotions) are of higher median amplitude in young people than in elderly subjects: 9.4 mV (95% CI, 8.8-10.0 mV) and 4.6 mV (95% CI, 4.1-7.4 mV), respectively (p less than 0.05). The vasomotion frequency was similar in both age groups. At 44 degrees C skin temperature, the median CBFV peak in the young was 163 mV (95% CI, 128-192 mV), as opposed to 102 mV (95% CI, 92-124 mV) in the aged subjects (p less than 0.0005). The median increment in CBFV, driven by every heart beat, was also higher in the young age group: 86 mV (95% CI, 76.4-96.0 mV) compared with the elderly group: 63 mV (95% CI, 50-72 mV, p less than 0.005). Considering the fact that the magnitude but not the pattern of skin perfusion varied between the two groups, we conclude that ageing is associated with loss of capillary plexus functional units, and therefore the skin perfusion is lower in aged people.

Adult↗
PubMed1992

Effects of noise and noise suppression on speech perception by cochlear implant users.

The recognition of phonemes in consonant-vowel-consonant words, presented in speech-shaped random noise, was measured as a function of signal to noise ratio (S/N) in 10 normally hearing adults and 10 successful adult users of the Nucleus cochlear implant. Optimal scores (measured at a S/N of +25 dB) were 98% for the average normal subject and 42% for the average implantee. Phoneme recognition threshold was defined as the S/N at which the phoneme recognition score fell to 50% of its optimal value. This threshold was -2 dB for the average normal subject and +9 dB for the average implantee. Application of a digital noise suppression algorithm (INTEL) to the mixed speech plus noise signal had no effect on the optimal phoneme recognition score of either group or on the phoneme recognition threshold of the normal group. It did, however, improve the phoneme recognition threshold of the implant group by an average of 4 to 5 dB. These findings illustrate the noise susceptibility of Nucleus cochlear implant users and suggest that single-channel digital noise reduction techniques may offer some relief from this problem.

Adult↗
PubMed1992

Carotid body tumor: diagnostic and therapeutic approach.

Carotid body tumor may be clinically suspected when the only clues are physiologic manifestations of carotid body dysfunction or when a palpable cervical mass is evident upon presentation. In the latter case, the physiologic signs of carotid body dysfunction are usually recognizable. We have presented the case of a patient who was completely disabled by a slowly enlarging carotid body tumor. An attempt at surgical excision of the tumor was unsuccessful because of its proximity and adhesion to vital neck structures. An endocardial pacemaker inserted to ameliorate the episodes of bradycardia and hypotension accompanied by transient complete atrioventricular block resulted in only partial and temporary relief. Finally, irradiation of the tumor induced fast shrinkage and rapid regression of symptoms.

Carotid Body Tumor↗
PubMed1992

Speech recognition performance on a modified nonsense syllable test.

A modification of the City University of New York nonsense syllable test (CUNY NST) has been developed in which (a) the several subtests of the original test are replaced with a 22-item consonant-vowel (CV) subtest and a 16-item vowel-consonant (VC) subtest; and, (b) the response choices for each target syllable include all 22 initial and all 16 final consonants, respectively. In addition, the test tokens are presented as isolated syllables without a carrier phrase. These changes enable the resolution of confusions not possible on the original NST, and also the construction of a single confusion matrix each for CVs and VCs, respectively. The modified nonsense syllable test (MNST) provides results that compare favorably to those of the original NST.

Adult↗
PubMed1992

[Flow cytometric analysis in non-small-cell bronchial carcinoma and its prognostic significance].

Tumor and lymph node infiltration, and the DNA-ploidy status of a tumor contain prognostic information in addition to the information obtained by histological examination of surgical samples. Specimens from 112 patients with non-small-cell lung carcinoma obtained immediately after surgery were investigated by means of flow cytometry. DNA-aneuploidy was found in 43% of the primary tumors. Independent from tumor stage, patients with DNA-euploid tumors lived significantly longer (p less than 0.01) than with DNA-aneuploid carcinomas. In 29 cases the DNA-ploidy status of the primary tumor (PTU) could be compared with that of the N2 lymph node metastases (LM). 7 samples revealed a change from DNA aneuploidy in the PTU to DNA-euploidy in the LM. Patients with DNA-euploid PTU and DNA-euploid LM lived significantly longer than patients with DNA-aneuploid PTU/DNA-euploid LM, and patients with DNA-aneuploid PTU/DNA-aneuploid LM. In case of lymph node infiltration only the simultaneous measurement of DNA ploidy of PTU and LM offers an accurate prognostic evaluation. Local tumor recurrence exhibited stability of DNA ploidy, showing DNA euploidy in 12 out of 13 PTU and their corresponding recurrent tumor. Thus, the DNA-ploidy status offers additional prognostic informations which is useful for an extended tumor classification.

Carcinoma, Non-Small-Cell Lung↗
PubMed1992

Prognostic value of deoxyribonucleic acid aneuploidy in primary non-small-cell lung carcinomas and their metastases.

The ploidy status of the deoxyribonucleic acid of a malignant lung tumor provides additional information besides histologic grading and tumor staging according to lymph node infiltration and tumor metastasis. Ninety-nine surgical specimens from patients with non-small-cell lung carcinoma were investigated by flow cytometry. Deoxyribonucleic acid aneuploidy was found in 48% of the primary tumors. Patients with deoxyribonucleic acid-euploid tumors showed better survival (p < 0.01) than those with deoxyribonucleic acid-aneuploid carcinomas independent of tumor stage. Deoxyribonucleic acid ploidy status of the primary tumor was compared with that of N2 lymph node metastases in 29 cases. Seven samples showed a change from deoxyribonucleic acid aneuploidy in the primary tumor to deoxyribonucleic acid euploidy in the lymph node metastases. Survival was significantly better for patients with euploid primary tumors and lymph node metastases, followed by patients with deoxyribonucleic acid-aneuploid primary tumors and euploid lymph node metastases. Survival was poorest in patients with deoxyribonucleic acid-aneuploid primary tumors and lymph node metastases. It was observed that only the simultaneous determination of deoxyribonucleic acid ploidy of primary tumors and lymph node metastases permits accurate prognostic evaluation in case of lymph node infiltration.

Actuarial Analysis↗